Eating out. According to Shepherd Works eating small amounts of FODMAP foods when dining out may not induce IBS symptoms even if you are very sensitive. Reducing your FODMAP intake for 1-3 days prior to dining out may minimise the symptoms.*If going to a restaurant I usually see if friends will let me choose where we go and then I can pick somewhere that at least has some simple/basic foods on the menu (eg steak and salad/veges) - and I ask for sauces to be served on the side. We would usually avoid certain types of restaurants if daughter was coming out with us eg. Thai, Indian, etc, as usually lots of onion, garlic etc in their recipes and it's too difficult for those sorts of places to adjust their recipes or provide suitable alternatives.
*I sometimes ring the restaurant a few days before (or 'hostess' if going to a friends house) and just say my daughter has some dietary problems; rather than telling them all the things she can't have (although usually mention onion, garlic and wheat), I give them a few ideas of what she can eat. I have found most places/people to be very accommodating once you have given them some easy suggestions.
*Worst case scenario, eat before you go out so you're not starving, and take some FODMAP friendly snacks with you.
Lactose Intolerance. Lacteeze tablets (or other brands) replace the lactase in your small intestine that normally break down lactose into 2 smaller more digestible molecules. Chew tablet/s with first mouthful of a lactose-containing meal (number required depends on amount of lactose in meal and individual lactose sensitivity). Worth a try - I imagine they would be handy at least when dining out, etc.
Try not to let it ruin your social life. Hopefully once you've been on the FODMAP diet for a while your IBS symptoms will be under control.